time all 6 cylinders

**redsnapper386** · 01-14-2023, 12:28 AM

guys 1993 2.5 v6 would timeing all 6 cyls help a hard to start issue as well as rough idle sneezing ive only been timeing no 1 at 25 deg and i still have issues thanks

**rgsauger** · 01-14-2023, 02:08 AM

Is this a carb or EFI motor? Have you replaced the factory reeds with a good set of aftermarket ones from Chris Carson or others? I don’t think that your issue is in timing. It is never a bad idea to check all six but I don’t think that’s your issue. Have you done a compression test recently?

**redsnapper386** · 01-14-2023, 02:34 AM

carb cc reeds comp good this mtr is all rebuilt new every thing carbs are wmh 1a they had 46 idle jets so came down to 40 with no change comp is in the 130s i will look for a vac leak tomorrow since rebuild its very hard to start when cold ok after warm up but tack jumps arround under 1600 rpms sneezes hesitates the mtr simply will not idle nice if i bring the idle speed up arround 1300 it gets better but too high for shifting thanks

**25two.stroke** · 01-14-2023, 03:03 PM

Sounds like you have a vacuum leak, a crack in a bleeder line, or the base timing is way off.
When you say the tachometer jumps around...how many rpms does it jump? Is the motor changing rpms causing it to jump, or does the tach actually look like its going haywire?

**redsnapper386** · 01-14-2023, 04:09 PM

in neutral it jumps from 800 up to 1600 rpms its definately in the motor tacks are new i will recheck timeing also bleed lines are new no leaks thanks for help

**Baker343** · 01-14-2023, 07:19 PM

I'm thinking fuel delivery issue. Verify reeds are still intact and I would throw on a set of reliable WH carbs before you dive into electrical fun

**Baker343** · 01-14-2023, 08:01 PM

Rebuild your fuel pump first

**25two.stroke** · 01-14-2023, 09:56 PM

So as I understand the motor is surging like 800 rpms at idle? I was asking about the tach not because I thought your tach was bad/old, but sometimes the tach acting erratically but the motor not sounding like its changing rpm can indicate a stator issue or a voltage issue.

If the motor itself is surging a lot then you are likely picking and dropping 2 cylinders. 1 carb can do that to you if the idle circuit is plugged or the float set wrong. Ignition can also do that to you. You noted that you set the timing at 25 btdc; did you also check the base timing? And have you tried running it with the idle stabilizer removed (if you still have it on your motor)?

**Baker343** · 01-14-2023, 10:35 PM

Originally Posted by 25two.stroke

So as I understand the motor is surging like 800 rpms at idle? I was asking about the tach not because I thought your tach was bad/old, but sometimes the tach acting erratically but the motor not sounding like its changing rpm can indicate a stator issue or a voltage issue.

If the motor itself is surging a lot then you are likely picking and dropping 2 cylinders. 1 carb can do that to you if the idle circuit is plugged or the float set wrong. Ignition can also do that to you. You noted that you set the timing at 25 btdc; did you also check the base timing? And have you tried running it with the idle stabilizer removed (if you still have it on your motor)?

Don't over think it. Start with the fuel delivery and element that first.

**OnPad** · 01-14-2023, 10:35 PM

You've been fighting this engine awhile now!

It never hurts checking your timing on all six, will rule out double fire. Also if pushing a full 25°, probably mandatory.

It really sounds like what the guys have mentioned above.

Hard start and sneaze is indicative of fuel starvation, massive air leak, or timing problem. Surging is usually caused by fuel starvation or air leak.

You might be able to put compressed air, or vacuum, at each spark plug hole, piston at tbc, and check for air leak. I wouldn't recommend using any more than about 10psi. I've never tried it, so I don't know how well it will work? Might have to block the intake manifold in order to hear leak?

Fuel pressure would also be a good check. Boat tanks, alot of times have a check valve in em, can be problematic. Or you could have air leak in fuel hose?

**Baker343** · 01-14-2023, 10:53 PM

I fought the same issue's you are describing and it ended up being a tired fuel pump diagram. Throwing money at that is good maintenance

**Baker343** · 01-14-2023, 11:39 PM

The fuel pump diagram takes a pulse off one of the cylinders and when it quits it leaks fuel in that cylinder and it causes a lot of problems you are describing. Someone will elaborate more.

**rgsauger** · 01-15-2023, 12:28 AM

Regarding the fuel pump, the little air line from which it gets it’s signal can also degrade and leak and cause probs. Dirt simple to rebuild and rule out